The WHY he decided to commit fraud is a nice detail but literally has zero bearing on if Trump actually did the whole I said the money was for ABC but it was really for XYZ.

Actually this isn’t true, the why is very central to the case. The prosecution’s argument is that the “why” is that it would’ve been damaging to his campaign. That is what links it to the campaign finance law, and what makes it a felony offense. This is an element that they will need to prove in court.

The falsifying business records piece is pretty much a slam dunk.